Medical imaging apparatuses, such as a magnetic resonance imaging (hereinafter referred to as an MRI) apparatus and a CT apparatus, have a structure in which an object is mounted on a bed and the bed is inserted into an imaging space of an apparatus main body. Therefore, the bed has a complicated configuration including a lifting mechanism that lifts a top plate, on which the object is mounted, to the height of the imaging space of the apparatus main body, a horizontal movement mechanism that horizontally moves the top plate in order to insert an imaging site of the object up to the center of the imaging space, a control unit that performs the movement according to a control signal from the apparatus main body, or the like. For this reason, the bed usually has a weight of hundreds of kilograms, is precisely positioned, and is mechanically and electrically connected to the apparatus main body.
In recent years, for an improvement in the throughput of examination for objects, beds that are usable after being separated from the apparatus main body are required. For example, in the case of an object that cannot enter a bed by itself, the work of transporting the object, which is transported to the vicinity of the bed, lifting the object by two or more examiners, and mounting and fixing the object to the bed is required, and examiner's burden is great. Particularly in the case of an MRI apparatus, metallic mobile beds, such as a usual stretcher, are drawn close to the apparatus main body by a strong magnetic field generated from the apparatus main body. Therefore, the object cannot be transported to the side of a bed fixed to the MRI apparatus by the usual mobile beds. Therefore, in the related art, an object is transported in a procedure of transferring the object from the usual stretcher to a special stretcher made of a nonmagnetic substance in the lobby of an examination room, and transporting the object to the side of the bed of the MRI apparatus. In this case, a transfer from a bed to the usual stretcher, a transfer from the usual stretcher to the nonmagnetic stretcher, and a transfer from the non-magnetic stretcher to the bed of the MRI apparatus are required, and the number of transfer times is three.
Therefore, if the bed of the MRI apparatus can be separated from the main body and be pushed with the hands and moved to the lobby of the examination room or the bedside of an object, and the object can be directly transferred from the usual stretcher or bed to the bed of the MRI apparatus, the number of times of transfer can be reduced. Accordingly, not only can an improvement in the throughput of examination be realized, but also a burden on the object can be reduced.
A bed that is attachable to and detachable from a main body of an MRI apparatus is disclosed in PTL 1. In this technique, as shown in FIGS. 1 to 5 of PTL 1, a front lower portion of the apparatus main body is equipped with a docking mechanism 16, such as a guide 24 having a conical outer shape. Meanwhile, a lower portion of a front end of a bed is equipped with a coupling mechanism to be coupled to the docking mechanism 16. When the bed is coupled to the apparatus main body, the bed is brought close to the apparatus main body until a lateral plate 100 arranged at a front end portion of the bed bumps against docking points 32 and 34 on both sides of an upper portion of the conical guide 24 of the apparatus main body. The movement of the bed at this time is guided as a pair of pins 96 and 98 below the lateral plate 100 are inserted so as to run along the conical guide 24 of the apparatus main body. If the lateral plate 100 of the bed bumps against the docking point 32, the bed is fixed to the apparatus main body by coupling a latch hook 58 of a lower portion of the bed to a pin member 56 at the tip of the conical guide 24 of the apparatus main body.